As a rule angle drive gearboxes consist of two bevel gears meshing with each other that are provided with differing diameters corresponding to the desired gear ratio. Frequently a relatively small pinion is used here as driving bevel gear which drives a relatively large ring gear in order to attain a large gear speed reduction ratio or a transmission of large torques. In special areas of application in which very compact configurations are demanded together with a guarantee of high gear reduction or step-up ratios, such as are required for motor vehicles or for agricultural or construction machines or utility vehicles as well as possibly for machine tools, angle gearboxes of the type applied in the past are at the limit of their capability. In particular in connection with drive components, such as differential gearboxes or differential, angle gearboxes in compact configuration with high step-up or reduction gear ratios and with high torque transmission capacities are demanded. The requirement for high torque transmission capacity leads, in particular with angle drive gearboxes, to problems that are difficult to overcome in the configurations of the bearing supports for the bevel gears, the input and output drive axles in regard to allowable deflections and in the selection of materials with respect to the required strengths for the transmission of the required forces. These problems can frequently be solved only at the cost of the size and the complexity of the configuration and the number of parts and the higher costs of the gearbox associated with it.
In order to increase the possible torque transmission capacity of angle drive gearboxes, angle gear drives have been developed upon the background of torque division that are provided with double bevel gear stages arranged in mirror image manner whose torque division branches are combined again over additional gearbox components or supplementary gearboxes or summing gearboxes. The result is that the input forces that can be transmitted are divided among two bevel gear stages. Thereby the required dimensions of the ring gears can be reduced and smaller configurations can be achieved.
For example DE 100 65 107 A1 discloses a torque division angle drive gearbox which is provided with a bevel gear that meshes with two ring gears arranged in mirror image manner. The torque is combined in additional intermediate gears arranged between the ring gears. As limited by this configuration this gearbox reduces or increases the rotational speed ratio of the main drive and the ring gear and therefore can deliver only limited reduction or speed increase ratios. Here the speed reductions or increases are directly connected with an increase in the volume of the configuration or the diameter of the ring gears. For an application as a compact component of a drive this angle drive gearbox is therefore very inappropriate.
Furthermore DE 40 41 898 A1 discloses an angle drive gearbox with torque division that is provided with bevel gears driving each other where a bevel gear configured as an intermediate bevel gear drives two bevel gears configured as ring gears or is driven by these. Here the torque is combined in a multiple gear ratio planetary gearbox connected to the ring gears. Here the disadvantage is that due to the high cost configuration of the multiple gear ratio planetary gearbox, with several planets located on a planet axis alongside each other, for one the volume of the configuration is very high and for another the number of component parts is very large. Here these characteristics also prove disadvantageous for an application in connection with differential gearboxes.
The task underlying the invention is seen in the need to define a torque division angle drive gearbox as defined initially through which the aforementioned problems are overcome. In particular an angle drive gearbox is to be created that makes possible a high torque transmission with low component volume and low numbers of component parts and that is provided with a low deflection of the input or the output shafts. Furthermore the configuration of the angle drive gearbox should be such that an integration of an axle-end drive can be used without any significant constructive limitations.